Bug or Hidden item?

I found a small group of random champs not belonging to anyone behind my arena behind a tree, when I clicked on them they disappeared and an item took their place. The item switched between what it was, but I could not pick it up. In the next game I played I did not have it in my arena but some one else did. I had lost and was spectating to see if I could find that "glitch" again, and same thing happened except I could pick up the champ and after they disappeared I could pick up the item but I could not do anything with either... I tried telling them about it but they just mocked me like I was crazy and or pointing out something obvious everyone knew about... Anyone know what that stuff was? Is that how some people have more items than others and I just can't figure out how to pick it up? Is it just random extra crap the game didn't know what to do with so it shoved it off to the side like a glitch? ???